Field of the Disclosure
The disclosure relates to a signal processing method based on Code Division Multiple Access (CDMA) technology, more particularly, a communication receiving apparatus, a signal receiving method thereof, a signal processing method, and a signal transmitting method.
Description of Related Art
Current electronic devices (e.g. mobile phones, DVD, fiber optics communication, digital TV set-top boxes) are digital structures which are capable of transmitting millions of bit code such as 0 and 1 within a second. Owing to efficiency of encoding technology, errors seldom occur even for such rapid communication transmission with mass data volume. The following example is used to explain encoding technology of communication. Suppose there are three brothers in the Chen family whose names are Chen O, Chen Q, and Chen D. Due to the similarity of their first names, it is easy to get their names mixed up. However, the number of words can be increased (e.g. Chen A O, Chen B Q, and Chen C D). This way, even when the last letter of the name is mistaken, the recipient can automatically correct the mistake through identifying the inserted channel codes (such as A, B, and C). Therefore, the sprit of encoding is adding identification codes into original codes to increase the differences between the transmitted data and thereby decrease the chances of error occurring, and this technology is called the channel coding theory.
CDMA is one of the encoding technologies as described above. It started as a military communication technology, and in around 2000 became a key technology of the third generation (3G) mobile communication standard (e.g. Wideband Code Division Multiple Access (W-CDMA)). Using CDMA technology to encode and decode data can greatly increase utilization rate of wireless channels and increase the ability to reduce interference. The encoding and decoding usually utilizes spread codes (e.g. pseudo-noise (PN) sequence, Walsh code, etc) to encode data sequence to implement spread signal technology.